The procedure however went awry, and Bug was transformed into a hideous mutant. Upon discovering this he went on a rampage, destroying Geoffrey's lab and grievously injuring the geneticist.
While he doesn't appear in it, his next mention is in Is it She? where he manages to shoot Rosa. In the following chapter, No More Chase, he reveals himself and fights with Greybane. While Greybane manages to defeat him, he is unable to kill him, the pair being captured by a machine.
Although Bug makes no further appearances he was, along with Greybane, taken to the Machine City (though it is unknown whether he was processed or not). He is believed to have died there.
As a mutant Bug seemed to have no, or at least a minimal personality. Nothing is known about his personality as a human.
Bug's exact relationship with Greybane prior to the story is unknown. Although they would have known each other, they don't appear to have been close friends. Despite this Greybane does refer to him as his old friend at one point.
As with all mutants Bug is assumed to have been stronger than the normal human. Being of a superior strain however Bug had the ability to speak, to use a weapon and could also command a group of mutants apparently loyal to him.